Conventionally, a vibration actuator has been mounted as a vibration source in portable devices having a vibrating function. It is possible to notify a user of an incoming call and to improve an operational feeling and/or realism by driving the vibration actuator to transmit vibration to the user. Here, the “portable devices” include portable communication terminals such as mobile phones and smartphones, personal digital assistants such as tablet PCs, portable game terminals, a controller (game pad) of stationary game machines, and wearable terminals to be worn on clothes and/or a wrist.
Vibration actuators disclosed in Patent Literature (hereinafter, referred to as “PTL”) 1 (Japanese Patent Application Laid-Open No. 2015-095943), PTL 2 (Japanese Patent Application Laid-Open No. 2015-112013), and PTL 3 (Japanese Patent No. 4875133) include a fixing part including a coil, and a movable part including a magnet, and in such vibration actuators, vibration is generated by utilizing a driving force of a voice coil motor composed of the coil and the magnet to cause the movable part to reciprocate. Each of these vibration actuators is a linear actuator in which the movable part moves in a straight line along a shaft, and is mounted such that the vibrating direction is parallel to the main face of a portable device. Vibration in the direction along the body surface of a user is transmitted to the body surface being in contact with the portable device.